Sleeve check valve



JUL l2, 1960 R. P. YouNGHAus 2.9205645 sLEEvs CHECK VALVE Filed Jan. 11,1957 /lca/'c/ f. younyar/.r

INVENTOR.

BYMM

United States Patent O 2,920,645 SLEEVE CHECK vALvE l P. Ynunghaus,Illouston, Tex.

nppuauenlanmy 11, 1951 serial Nn. 633,591 i l' s (ci. rs1-496) -Myinventionrelates to a sleeve check valve, primarily adapdfforpreventing'back ow through a line. It may Ud Suc'essfully used in flow'systems for gases or liquids.

I'n thernpreiconventional type of check valve, a device is'e'tiip'loyed'wliich utilizes either a hinged ap or a steelhalf,roperating on' afvalve' seat. There are certain weakdssesninhernt inthis type 4of device. Some can be installed only in a vertical positionand most exhibit a tendency reward undue wea; on the nexible sean of thevalve "Where'high pressures or sudden and severe var-iain pressure areencountered. In addition, abrasion in t'lfe vvalve seat sometimes occursdue to foreign particles in the movingv fluid or gas. The necessity forobtaining a tight seal naround the flap or ball precludes the eofrnate'rial in the valve seat which is hard enough to resist therwearof frequent or violent closings.

Valves which have designed to overcome these shorthave been too complexto provide trouble-free operation, or too' expensive to be economically'feasible, 0.1." .bethl It is therefore an object of my invention toprovide a valvewhichv is simple and rugged inl construction, operable inan'y position and economical in cost.

It' is a further object of my invention to provide a p istgnj operatedcheek valve which opens and closes in resppuseto thepressure dierentialbetween its inlet andk A further obit-.Ci of my invention is to providea piston operated valve which will resist the wear of frequent orextreme variations in operating pressure because of the arrangementofthe exible seals.

'A furtherk Objectis to provide a valve with design features to limit orrestrain violent engagement or chatter la valve members- Tis au furtherobjectr of my invention to provide a` valve having design features topredetermine the preslreldjlferential which will bring about operationof the I ii, fcaljrying out my invention I propose a sleeve cheekV valve'which employsy a double acting piston to bring alieuttheopeningorclosing of the valve. By directing inlet. pressure tojone Side of thispiston and outlet pressre' 't .t h e other,x the piston can be rnade tomove in its cyljitlei; toproduce a closed or opened valve position in'gse to the inlet-outlet pressure differential. The entialj pressurerequiredl to, produce piston movenigrttris preferably, determined indesign by reducing the enve, areay of the appropriate pressure` face ofthe Biw. For normal operation it is, necessary that the pistnnbe biasedAtoward the valve closed position under agualizedptessure-j While myinvention may take different specific forms, Lhlqve.shoWnitl` theaccompanying drawing, one embodimegtin whighthe detailsof myinventionmay be il1u s InFig. l` is shown acut-away view of inyvalve inthe limsi am..

outlet.Y

'2,920,645 Patented Jan. 12, 1960 Fig. 2 represents the same view withthe valve in the open position.

Referring now to the drawings and particularly to Fig. 1, the numeral 1indicates the inlet of the valve and the numeral 2 indicates the outletof the valve. Normal ow moves from inlet 1 to outlet 2 and the valveoperates to prevent ow in the reverse direction. The valve is adapted tobe threadably or otherwise attachable for interposition in a fluidsystem.

The cylindrical sleeve 3 housing the valve is threadably joined at 4 toa radial flange extending from a closed cylinder 5. The cylinder 5 isspaced from the sleeve 3` at one end by the flange and at the other endby a plurality of lugs 6. The resultant annular passageway 7 between thesleeve and the cylinder is in open communication with the inlet 1. Aplurality of openings or ports 8 extends through the wall of cylinder 5to form a means of communication between the passageway 7 and the insideof cylinder 5.

Inside the cylinder 5 is slidably mounted the piston 9v which isprovided with O-rings 10, 11, and 12 for sealing against the internalwall of the cylinder 5. Through the lateral cylindrical wall of thepiston 9 is a plurality of flow ports 13 in axial alignment with theopenings 8. Thel flow ports 13 are moved by reciprocation of the pistonbetween extreme positions of misalignment and full alignment with theopenings 8, defining the fully opened and fully closed states of thevalve. Alignment of t-he ow ports 13` with the openings 8 allows ow fromthe inlet 1l through the passageway 7, the openings 8 and the llow ports13, and thence to the outlet 2. The cross sectional rea Vof'y theopenings 8 and flow ports 13 may be made'equal to that of the inlet ofthe valve in order to insure full line ow.

The fully opened and fully closed positions of the piston are defined bythe opposite limits of its stroke.`

Thus, its forward or valve closed position is defined by an inwardextension 14 at the closed end 15 of cylinderv 5 and its rearwardforvalve open position by a piston stop 16. These positions are illustratedin Fig. l andI 2, respectively.

A circumferential groove 17 extends` `around the exl terviorjl of the,piston to interconnect the ow ports 13.

This eliminates the1 necessity for positive guides to bring the flowports` 13 into exact axial alignment with the openings 8', for thegroove 17 will allow communication between the separateflow portsk 13.Consequently, mere radial alignment of the ports 13 and the openings 8will Produce the desired flow through the valve. A portion o f thefluidintroduced into the valve through the inletl 1 is bypassed throughan orifice 18 through the end wall 15 of the cylinder 5, to act on theforward face of the pist/on 9,. Preferably, the orifice 18 opens intothe annular chamber 19 surrounding the extension 14 on the end wall 15of the cylinder 5 to provide for distribution of pressure over theforward face of the piston. Hence it isy inlet fluidg pressure in thechamber 19 that tendsvto drivethe piston rearward.

In the forward face of the piston 9 is a cylindrical bore 20 whichaccommodates an auxiliary piston 21. O-ring seal 22 is providedonauxiliary piston 21 to prev ent leakage of inletpressure from withinthe cylinder Sinto the bore, 20; As the piston 9 slides, the cylindricalbore 20'm0ves with relation to the stationary piston 21'. Axiallythrough the body of piston 22 is a vent line 23 which exhausts throughsuitable tubing 24 to a space of reduced pressure, fory example theatmosphere, to minimize resistance to movement of the piston 9 along theauxiliary piston 21. The primary function of the auxiliary pistonrZlisto reduce the eective area of the for'-v 3 ward face 25 of piston 9 tothe annular area surrounding bore 21.

If desired, as either an alternate or additional feature, a key 26 maybe provided. on piston 9 `to operate in key slot '27 to preventvrelative rotation between the piston 9 and the cylinder 5 and hence,insure axial alignment of the ow ports 13 with openings 8.

Back pressure in the system in which the valve is used is of courseopenly communicated through outlet 2 to the interior of cylinder 5 toact on the composite back face of the piston 9 comprising the centercircular surface 2S, the annular area 29 surrounding theauxiliarycylinder 28, and the annular area 30 at the rear edge. This pressuredrives the piston 9 forward. Since the area of the composite back faceofthe piston is substantially equal to the cross sectional area of thecylinder, and therefore exceeds the area of the front face by an amountequal to the cross sectional area of the bore 20, the piston will bebiased toward its fully closed position shown in Fig. 1 when the inletpressure and back pressure are equalized.

In operation the speed with which the piston 9 moves is a function ofthe speed with which'uid can enter or leave the space 19 through orificel18. In designing a valve of this type for a specific installation theviscosity of the fluid to be handled and the expected variations inoperating pressure can be considered in selecting an orifice size whichwill produce quiet operation, free of valve chatter, and precludeviolent valve engagement.

For valve installations which are not self-lubricating, a lubricationtting 31 is provided. Suitabley lubricants introduced at this point aredirected through tubing 32 to the space between the internal walls ofthe cylinder and the piston 9.

It is anticipated that in some installations of this valve, suddenpressure differentials may be encountered. To prevent, in suchcontingency, any damage to the central O-ring seal 11 as the piston 9moves rearward, 'a plurality of relief holes 33 are provided. Theseholes are for the purpose of introducing inlet pressure into the spacebetween the external walls of piston 9 and the internal walls ofcylinder 5 at a point on the side of O-ring 11 opposite the opening 8.This serves to approximately equalize the pressures on each side of theO-ring as it nears opening 8, and prevents its being squeezed out andpinched against the edge of the opening. The problem solved by theserelief holes is present in all piston operated valves which involve theuse of a flexible seal which slides by a lateral opening in the cylinderwall. Pressure which acts against only one side of the seal during itssliding movement tends to deform the seal and force it from its seatinto a position where it may be damaged by the edges of the opening.` Myinvention extends the field of useful application of this type of sealinto an area heretofore considered u nfeasible.

Although I have described my invention as a check valve, it may be usedas a safety or pressure relief valve with no structural changes. Insteadof preventing back flow through a line, it could function to preventpressure in a chamber from exceeding a certain point, so long as thatpoint was measured in terms of its differential with regard to thepressure which was supplied to the outlet chamber of the valve.

' While one embodiment of my invention has been shown and described, itis obvious that many modifications thereof can be made by one skilled inthe art without departing from the spirit of my invention. It istherefore, desired to protect by Letters Patent all forms of theinvention falling within the scope of the following claims.

I claim:

1. A sleeve check valve comprising a valve. bodysaid valve body having abore therein, a double acting pistonslidable within said bore, anupstream owpassageway www@ ,t0 Said .Valve body and Opening im@ sa??b9?? at a point intermediate the ends thereof, a pressure conduitinterconnecting said upstream ow passageway and the forward end of saidbore, a downstream flow passageway opening from the rearward end of saidbore behind said piston, a valve member carried by said piston andextending rearward therefrom to cover said upstream flow passagewayopening throughout said piston's stroke,

a port through said valve member so situated as to be in communicationwith said upstream passageway opening when said piston is moved towardthe rearward end of said bore, a plunger and a receptacle slidablyreceiving said plunger on the upstream side of` said piston, one of saidplunger and receptacle being on said piston and the stream ow passagewayand the forward end of said bore,

a downstream ow passageway opening from the rearward end of said bore,la valve member carried by said piston and extending rearward from saidpiston. to ,cover said upstream ow passageway opening throughout saidpistons stroke, a port through said valve member so situated as to be incommunication with-said upstream passageway opening when said. piston isin a rearward position, an auxiliary bore extending into the forwardface of said piston, an auxiliary piston fixed to said valveV body andslidable within said auxiliary bore and a venting conduitinterconnecting said auxiliary bore in front of said auxiliary pistonand a space of reduced pressure.

3. A sleevecheck valve comprising a valve housing, said valvehousinghaving an inlet opening through one wall thereof, a valve bodyextending through another wall of said valve housing, said valve bodybeing spaced within said housing to form av valve -chamber therearound,said valve body having an axial bore, extending into said valve bodyfromoutside said valve housing with an open endl outside said valvehousing and closed end within said valve housing, lateral openings insaid valve body interconnecting said valve chamber andsaid boreintermediate said ends, a double acting piston slidably located withinsaid bore and operable over a distance between said lateral openings andsaid closed end `of said bore, a pressure conduit through said valvebody interconnecting said valve chamber and said closed end of saidbore, a valve closing member carried by said piston and extending towardsaid open `end of said bore to cover said lateral openings throughoutlthe stroke of said piston, ports through said valve memberv so situatedas to be in communication with said lateral openings when said piston isat a position towardr the open end of said bore, an auxiliary boreextending into the forward face of said piston, an auxiliary pistonfixed to said valve body and located within said auxiliary bore,saidlpiston being slidable on said auxiliary piston, and a ventingconduit interconnecting said auxiliary bore in front of said auxiliarypiston and a space of reduced pressure.

4. A sleeve check valve comprising a'valve housing, said valve housinghaving an inlet opening throughone wall thereof, a valve body extendingthrough another wall of said valve housing, said valve body being spacedwithin said housing to form a valve chamber therearound, said valve bodyhaving an axial bore, extending into said valve body from outside saidvalve housing with an open'end outside said valvehousingand a closed endwithin saidvalve housing, Ylateral openings in.l said valve bodyinterconnecting said valve chamber and said bore intermediate said ends,lateral relief ports in said valve body interconnecting said valvechamber and said bore, said relief ports being spaced toward said closedend of said bore from said openings, a double acting piston slidablylocated within said bore and operable over a distance between saidlateral openings and said closed end of said bore, an annular grooveabout the periphery of said piston, a resilient annular seal carriedwithin said groove, a pressure conduit through said valve bodyinterconnecting said valve chamber and said closed end of said bore, avalve closing member carried by said piston and extending toward saidopen end of said bore to cover said lateral openings throughout thestroke of said piston, ports through said valve member so situated as tobe in communication with said lateral openings when said piston is at aposition toward the open end of said bore, an auxiliary bore extendinginto the forward face of said piston, an auxiliary piston fixed to saidvalve body and located within said auxiliary bore, said piston beingslidable on said auxiliary piston, and a venting conduit interconnectingsaid auxiliary bore in front of said auxiliary piston and a space ofreduced pressure.

5. A valve comprising a valve body, said valve body having a boretherein, a passageway connected to said valve body and terminating in aow port opening laterally into said bore, said passageway being in opencommunication with a source of pressure uid, a piston slidable withinsaid bore, means for moving said piston selectively to cover and uncoversaid ow port, a resilient sealing ring carried on said piston andmovable therewith across said ow port, and a relief port opening intosaid bore at a point spaced axially from said flow port in the directionfrom which said sealing ring moves with said piston across said flowport, said relief port being in communication with said source ofpressure uid.

References Cited in the le of this patent UNITED STATES PATENTS 759,396Rutenber May 10, 1904 836,347 Tittelback Nov. 20, 1906 1,950,847 HarrubMar. 13, 1934 2,361,225 Meyer Oct. 24, 1944 2,555,334 Green June 5, 19512,644,481 Perlman July 7, 1953

